Effects Of Exogenous Substances On Physiological Characteristics And Quality Indexes Of Upper Leaves Of Flue-Cured Tobacco

The upper leaves of flue-cured tobacco accounted for a large proportion in the yield and quality of whole plant tobacco.Its utilization value and quality were only slightly lower than that of middle tobacco leaves.And at the same time,improving the usability of upper leaves was one of the issues to be solved urgently.In this paper,I conducted two field trials in Pangu Township,Biyang County,Zhumadian City,Henan Province in 2016 to investigate the effects of gibberellin-potassium fertilizer interaction and different small-molecule organics on the physiological characteristics and quality indexes of upper leaves of flue-cured tobacco.The different regulation effects of the leaves are selected to select the optimal treatment measures.The main conclusions were as follows:1.In order to explore the effects of interaction between gibberellin and potassium on physiological indexes of upper leaves in flue-cured tobacco,the tobacco leaves were sprayed gibberellin at the same time top dressed potassium on the day of topping,a field experiment was conducted to study the effects of interaction of gibberellin and potassium on the leaf area,antioxidant enzymes activity,carbon and nitrogen metabolism enzymes activity of flue-cured tobacco.The results showed that the interaction between gibberellin and potassium could significantly promote the development of the upper leaves,the effect of gibberellin was more obvious compared with potassium.The activity of SOD and POD in different treatments was basically the same with the extension of the growth period.The activity of antioxidant enzymes was significantly higher than CK,which indicated that the interaction between the gibberellin and potassium was effective to enhance the resistance and anti-aging ability.It was beneficial to the better growth and maturity of tobacco leaves.The activity of carbon and nitrogen metabolism enzymes in tobacco leaves was always higher than CK.The changes of enzymes activity were consistent at different periods,which indicated that the interaction between them could enhance the carbon and nitrogen metabolism intensity and conduct the generation of tobacco inner quality Compared with the lower level of gibberellin and potassium interaction on the interaction of higher had more significant effect on the physiological activity of tobacco.The effect of T4(20 mg·kg-1 GA3+10 kg K2SO4·666.7m-2)on the development of leaf,antioxidant enzymes,carbon and nitrogen metabolism enzymes were the best2.A field experiment was conducted to study the effects of interaction of gibberellin and potassium on the physical properties,chemical components and aroma quality of the upper leaves of flue-cured tobacco.Using the method of spaying two kinds of GA3 concentration and root application of two kinds of potash dosage on the topping day,the results showed:The interaction of gibberellin and potassium fertilizer could improve the leaf length,leaf width,single leaf weight and anti-tension of tobacco leaves,reduce the filling value and the percentage of stems,the overall quality of tobacco was better than the control.The interaction between gibberellin and potassium could increase the potassium content,potassium and chlorine ratio and reduce the nicotine,chlorine content,which coordinated the chemical composition and improve the quality of tobacco leaves.The interaction of gibberellin and potash could increase the contents of carotenoids,phenylalanines,Maillard reaction products,siclazid and neophytadiene in the upper leaves of flue-cured tobacco to varying degrees,and increase ?-Malaysia Ketones,megastigmatrienones,furfural,phenylethyl alcohol and other most of the various types of aroma compounds degradation products,significantly improve the total amount of neutral aroma substances,and reduce the content of solanone,tobacco aroma quality had been significantly improved.The effects of different intercropping treatments on the physical properties and aroma quality of tobacco leaves were not consistent.Higher GA3 and potassium application effect were better.The treatment of T4(20 mg·kg-1 GA3+10 kg K2SO4·666.7m-2)tobacco physical properties,chemical composition coordination and aroma quality were obviously dominant3.The effects of small molecular organic compounds on the leaf development,physiological characteristics,carbon and nitrogen metabolism and quality of flue-cured tobacco were studied by spraying different organic compounds(sucrose,sorbitol,sodium gluconate and glycine)on the day of topping.The results showed that:Spraying different small molecule organic compounds could promote the opening of upper tobacco leaves and increase the area of tobacco leaves Compared with the control,small molecular organic compounds could promote the antioxidant enzyme activities and the content of light and pigment in flue-cured tobacco leaves.The activities of superoxide dismutase(SOD)and peroxidase(POD)in tobacco leaves were significantly higher than those in control,and the content of malondialdehyde(MDA)in tobacco leaves was significantly lower than that in control.The contents of chlorophyll in tobacco leaves were increased by the treatments,but the content of carotenoids increased only by glycine treatment.The activity of amylase in tobacco leaves increased first and then decreased,and the nitrate reductase showed a decreasing trend.Glycine treatment promoted the metabolism of carbon and nitrogen.Sucrose and sodium gluconate were helpful for carbon metabolism,and sorbitol was more helpful to nitrogen metabolism in different treatments.The results showed that the spraying of different small molecule organic compounds could enhance the carbon and nitrogen metabolism of tobacco,but the performance was not consistent with each other.The contents of total sugar,reducing sugar,potassium,sugar and nicotine,potassium to chlorine ratio,total nitrogen,nicotine and chlorine in tobacco leaves were increased by spraying different organic compounds,which indicated that the treatment could effectively improve the coordination of chemical components And improve the quality of tobacco leaves.In general,the growth and the physiological activities of flue-cured tobacco were affected by the spraying of small molecular organic compounds.under the experimental conditions,glycine treatment promoted tobacco growth,enhanced enzymatic protection system,promoted carbon and nitrogen metabolism and improved tobacco leaves quality.